An alternative 7-ethoxyresorufin o-deethylase activity assay: A continuous visible spectrophotometric method for measurement of cytochrome P-450 monooxygenase activity

Klotz, Alan V.; Stegeman, John J.; Walsh, C.T.

doi:10.1016/0003-2697(84)90144-1

Cited by 306 publications

(91 citation statements)

References 10 publications

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“…The EROD level was determined according to the method of Klotz and Walsh (1984). The liver homogenate was mixed with 1.91 ml of re-suspension buffer (50 mM of Tris-HCl and 100 mM of EDTA, pH 7.4, 20 mg/ml of NADPH) and 2 mM of ethoxyresorufin and the absorbance was measured at 572 nm for 3 min in UV-vis spectrophotometer.…”

Section: Determination Of Erod Activitymentioning

confidence: 99%

Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis

Kalaiselvan

Muniasamy

Archunan

et al. 2015

Pharmaceutical Biology

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Context: Naturally occurring polyphenols including olive oil (OO) and its constituents hydroxytyrosol (HT) and tyrosol (TY), consumed in the Mediterranean diet, have shown to treat various ailments due to their remarkable antioxidant properties. Objective: The present study investigates the hepatoprotective effects of OO and its phenolic compounds HT and TY against TCDD-induced hepatotoxicity in male Wistar rats. Materials and methods: TCDD was administered at a dose of 100 ng/kg p.o. for 20 d. Administration of OO (10 ml/kg; oral), HT (0.5 mg/kg; oral), and TY (30 mg/kg; i.p) was started 5 d prior to TCDD administration, and continued for 25 d with or without TCDD administration. At the end of the experiment (25 d), blood was taken for biochemical analyses and liver for the measurement of macromolecular damages, antioxidant status, expressions of CYP1A1, and apoptotic factors. Results: TCDD administration resulted in significant (p50.05) increase in the level of hepatic stress markers ALT (101.6 ± 3.07 IU/l), AST (295.0 ± 3.0 IU/l), and ALP (266.66 ± 3.7 IU/l). Also, biochemical analyses of liver reported elevation in nitrite and protein carbonyl content and depletion of NQO1 and HO. However, OO, HT, and TY restored the antioxidant status. Protein expressions by Western Blot technique showed an increase in the level of CYP1A1 and Bax and a decreased level of Bcl-2 on TCDD treatment, and vice versa on OO, HT, and TY treatment. Discussion and conclusion: Our work concludes that dietary supplementation of OO, HT, and TY could serve as a potential preventive drug for TCDD-induced hepatotoxicity.

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Section: Determination Of Erod Activitymentioning

confidence: 99%

Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis

Kalaiselvan

Muniasamy

Archunan

et al. 2015

Pharmaceutical Biology

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“…From the post-raw mitochondrial supernatant, the soluble cytosol proteins were precipitated with chloroform and methanol according to Klotz's method. 28 The supernatant was quantified using Bio-Rad AC DC protein assay kit (Bio-Rad, Hercules, CA, USA) and aliquoted.…”

Section: Subcellular Fractionationmentioning

confidence: 99%

Arsenic trioxide and proteasome inhibitor bortezomib synergistically induce apoptosis in leukemic cells: the role of protein kinase Cδ

et al. 2007

Leukemia

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Arsenic trioxide (ATO) and proteasome inhibitor bortezomib have been successfully applied to treat acute promyelocytic leukemia (APL) and multiple myeloma (MM), respectively. Their synergistic effects with other anticancer drugs have been widely studied. Here, we investigated the potential synergy of bortezomib and ATO on Bcr-Abl þ leukemic K562 cells. The results showed that cotreatment of bortezomib at 32 nM, a half concentration for growth arrest, and ATO at 1 lM, a dose with no significant cytotoxic effect, synergistically induced apoptosis in the cell line, followed by enhanced mitochondrial dysfunction, release of cytochrome c and apoptosis-inducing factor, caspase-3 cleavage and degradation of poly-adenosine diphosphate-ribose polymerase together with the decreased Bcr-Abl protein. These two drugs synergistically induced proteolytic activation of protein kinase Cd (PKCd) with enhanced activation of two mitogen-activated protein kinases phospho-c-Jun NH 2 -terminal kinase and p38. The specific PKCd inhibitor rottlerin markedly decreased bortezomib plus ATO-induced apoptosis, suggesting that PKCd plays an important role in bortezomib plus ATO-induced apoptosis. Moreover, apoptosis synergy of bortezomib and ATO could also be seen in some kinds of acute leukemic cell lines and primary cells. Totally, our results indicate that combined regimen of bortezomib and ATO might be a potential therapeutic remedy for the treatment of leukemia.

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“…Reported resorufin molar extinction coefficients used to calculate concentration vary among laboratories. For example, van den Heuvel et al (1995b) reported a mean molar extinction coefficient of 54.0 ± 1.1 cm −1 mM −1 , and Klotz et al (1984) reported 73 cm −1 mM −1 . The extinction coefficient should therefore be reported along with the resorufin standard curve (Goksøyr and Förlin, 1992).…”

Section: E Measurement Of Cyp1a1 Catalytic Activity (Ahh or Erod)mentioning

confidence: 99%

The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

Whyte

Schmitt

Tillitt

2004

Critical Reviews in Toxicology

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ABSTRACT:The H4IIE cell bioassay has proven utility as a screening tool for planar halogenated hydrocarbons (PHHs) and structurally similar chemicals accumulated in organisms from the wild. This bioassay has additional applications in hazard assessment of PHH exposed populations. In this review, the toxicological principles, current protocols, performance criteria, and field applications for the assay are described. The H4IIE cell bioassay has several advantages over the analytical measurement of PHHs in environmental samples, but conclusions from studies can be strengthened when both bioassay and analytical chemistry data are presented together. Often, the bioassay results concur with biological effects in organisms and support direct measures of PHHs. For biomonitoring purposes and prioritization of PHH-contaminated environments, the H4IIE bioassay may be faster and less expensive than analytical measurements. The H4IIE cell bioassay can be used in combination with other biomarkers such as in vivo measurements of CYP1A1 induction to help pinpoint the sources and identities of dioxin-like chemicals. The number of studies that measure H4IIE-derived TCDD-EQs continues to increase, resulting in subtle improvements over time. Further experiments are required to determine if TCDD-EQs derived from mammalian cells are adequate predictors of toxicity to non-mammalian species. The H4IIE cell bioassay has been used in over 300 published studies, and its combination of speed, simplicity, and ability to integrate the effects of complex contaminant mixtures makes it a valuable addition to hazard assessment and biomonitoring studies.

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An alternative 7-ethoxyresorufin o-deethylase activity assay: A continuous visible spectrophotometric method for measurement of cytochrome P-450 monooxygenase activity

Cited by 306 publications

References 10 publications

Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis

Olive oil and its phenolic compounds (hydroxytyrosol and tyrosol) ameliorated TCDD-induced heptotoxicity in rats via inhibition of oxidative stress and apoptosis

Arsenic trioxide and proteasome inhibitor bortezomib synergistically induce apoptosis in leukemic cells: the role of protein kinase Cδ

The H4IIE Cell Bioassay as an Indicator of Dioxin-like Chemicals in Wildlife and the Environment

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